config: remove unrequired AC_HEADER_STDC
config: remove unrequired AC_HEADER_STDC

Autoconf says:
"This macro is obsolescent, as current systems have conforming
header files. New programs need not use this macro".

Signed-off-by: Gaetan Nadon <8a8cc541338200f67d4d0bcb65c78b6166649462@videotron.ca>

mad-s/xf86-input-synaptics-absolute,mad-s/xf86-input-synaptics-absolute